The invention relates to a device and method for jaw bone expansion, and more particularly, the invention relates to a device and method for creating traction on the upper jaw and dentition.
Bones sometimes develop at different rates, leaving some bones disproportionately shorter than other bones. Alternatively, injury may leave a bone shorter than its original length. Such a condition may lead to difficulties in a patient""s movement. For instance, a patient with a shortened tibia may need special shoes for assistance in walking. A small jaw can cause difficulties in chewing or breathing (obstructive sleep apnea). Moreover, deformations are often psychologically distressing to the patient, especially when the deformations occur in craniofacial bones.
One procedure for lengthening bones is referred to as osteosynthesis, osteogenesis, or osteodistraction. According to an osteogenesis procedure, an abnormally short bone is cut into two segments. The two segments are secured to a brace that permits the segments to be drawn apart. New bone then grows in the space between the separated bone segments, and eventually connects the two segments together into a lengthened bone. When the separated bone segments have been fully fused in this manner, the brace may be removed.
Many of the braces employed in osteogenesis procedures are simple mechanical bone fixation devices. Such devices have the shortcoming that they can not easily be adjusted once set. Other bracing devices are known, however, that allow the physician to periodically make adjustments in the brace during the lengthening procedure. For example, a physician may initially set such a brace so that a relatively short gap separates two bone segments. When new bone has filled in the gap between the two segments, the physician may adjust the brace such that the two bone segments are drawn farther apart, thereby creating a new gap. After bone has filled in the new gap between the two segments, the physician may once again draw the two segments farther apart. This procedure may be repeated as many times as necessary to lengthen the bone appropriately.
Conventional braces used for osteosynthesis are located external to the body. They attach to the bone through pins or screws. While these devices may achieve the desired end result of lengthening the deformed bone, they are unwieldy and unsightly, thereby preventing the user from engaging in many activities during the lengthening procedure. In addition, the mechanical advantage is less since there is a fulcrum effect on the long pins or screws. They also create unsightly scars where the pins extend through the skin. This scarring is particularly undesirable when they are located on the face.
Implantable bone distraction devices are described in U.S. Pat. Nos. 5,885,289 and 5,807,382 for extending bones of the skull. The implantable devices achieve the desired result of lengthening without the traumatic scaring and visible plates of the external devices. However, the implantable devices do not connect the right and left sides of the skull together to achieve better stability and simultaneous distraction with a single device.
Accordingly, it would be desirable to provide a maxillary distraction device that is totally inside the mouth to prevent unsightly visible plates and scarring and is bilateral in nature connecting the right and left halves of the midface across the midline.
The present invention relates to a device for maxillary jawbone expansion which is configured for mounting within the mouth and connects the right and left halves of the mid face and skull.
In accordance with one aspect of the present invention, a maxillary distraction device includes of at least two implantable anchors configured to be inserted into the bones of the malar region, a facebow configured to be positioned entirely within the mouth and to connect to one of the anchors on a right side malar region and to one of the anchors on a left side malar region, two vertical distraction screws for expanding the facebow vertically, and two anterior/posterior distraction screws for expanding the facebow horizontally.
In accordance with an additional aspect of the present invention, a maxillary distraction device includes of at least two implantable anchors configured to be implanted in the maxillary bones of the skull on opposite sides of a midline of the skull, and a facebow having two posterior ends connectable to the implantable anchors and configured to extend from the anchors entirely within the mouth across the midline of the skull, the facebow having at least one expandable section for bone lengthening.
In accordance with a further aspect of the invention, a method of performing osteogenesis of the maxillary bones includes the steps of implanting anchors in the right and left side maxillary bones, connecting a facebow to the anchors wherein the facebow extends entirely within the mouth across a midline of the patient, and lengthening the facebow periodically to lengthen the maxillary bones. Preferably, the facebow lengthens the maxillary bones and teeth in all three planes of space simultaneously.